Piston for oil-wells.



PATENTED JAN. 24, 1905.

G. A. MILLER. PISTON FOR OIL WELLS. APPLIOATIQN FILED 00T.2s.19o3.

UNITED STATES Patented January 24, 1905.

PATENT OFFICE.

PlsroN Fon OIL-WELLS. f

SPECIFICATION forming part of Letters Patent No. 780,518, dated January 24, 1905.

Application filed October 28,1903. Serial No. 178,918.

T0 all whom, it may concern:

Be it known that I, GLENN AUGUsTUs MIL- LER, a citizen of the United States, residing at Boulder, in the county of Boulder and State of Colorado, have invented a new and useful Pump-Piston for Oil-Wells, of which the following is a specification.

My invention relates to pump-pistons for wells, and more particularly for wells provided with a vcasing-as, for instance, oilwells, Sac.

In pumping oil great-difficulty is often eX- perienced in having the sand or other gritty material cutting out the leather washers or cups used for makin'gaclose joint and securing more prompt suction or action of the piston in operation.

The object of my invention is to prevent access of sand or other gritty material to the cups or washers, thereby preventing excessive wear as the piston is reciprocated within the working barrel. I accomplish this object by constructing a substantially cylindrical piston the central portion of which is reduced and the ends are in the form of hollow cylinv ders, the lower cylinder being open and the upper cylinder being provided with a suitable valve. p

In the accompanying drawings, in which the same letters of reference indicate corresponding parts in each of the views in which they occur, Figure 1 is a longitudinal sectional View of a portion of the working barrel of a pump with my improved piston in position therein. Fig. 2 is a similar View showing the piston in section. p

Referring to the drawings, A indicates a :section of the'casing of a well and which also spaced apart and held in positions by rings F,

formed of metal or other suitable material.

portion.

These rings E bear upon the bottom portions of the cups E, and the sides of the cups stand out clear of the rings andin contact with the inner face of the working barrel. The exterior diameter of the end cylinders are substantially equal to the diameters of the cups and are suflicient to cause a snug iitwith the interior of the working barrel when the parts are in position for operation. The upper end of the upper cylinder is provided with a suitable valve structure comprising a body portion G, having a longitudinal bore therethrough and a valve-cage H at its upper end. The lower end of the body may be reduced and screw-threaded for engaging with the Vupper end of the cylinder, and the intermediate portion maybe. square or angular for the reception of a wrench in securing it to the end of the cylinder. A valve I,.preferably a ball-valve, may be placed loosely within the cage and adaptedto rest upon its seat formed at the upper end of the bore through the body A suitable valve structure J is secured within the casing below the lower end of my improved piston and may be of any ordinary form.

By constructing a' piston as above described it is evident that when it is inserted in the working barrel the long cylindrical surface i of the cylinders at each end will prevent the y length of reciprocation of the pistons as compared with its length.

In operation the piston is inserted into the pump after being connected with the usual pump-rod and reciprocated in the ordinary manner. At any time that the cups become worn or need replacing the piston is separated, as by unscrewlng elther one of the cylinders from the central portion, after which the cup can be repaired or replaced and the parts screwed together again.

Although I have shown What I consider the best form of construction of my improved piston, it is evident that alterations or changes may be made therein, and I reserve the right to make all such changes as Will come Within the scope of my invention.

Having thus fully described my invention, What I claim as new, and desire to secure by Letters Patent, is-

A device of the kind described comprising a Working barrel, a piston consisting of end cylinders fitting snugly Within the barrel, and an intermediate section connecting the end cylinders, said section being of less diameter than the end cylinders, nuts connecting the reduced intermediate section to the end cylinders, a valve-cage having a threaded body portion secured in the upper end of onc of the end cylinders, said body portion having a bore formed longitudinally therethrough, a ball-valve in said cage, cups having a dialneter equal to that of the end cylinders, and rings spacing the cups apart, said cupsyand rings being carried by the intermediate section.

GLENN AUGUSTUS MILLER. Witnesses:

FRANK S. ADDINGTON, G. BURNHEART EYssnN. 

